1996 BMW 318i Exhaust

10
.
On
cars
built
up
to
3/95
:
Slide
control
unit
off
front
of
cylinder
head,
hand
turning
the
exhaust
sprocket
clock-
wise
(as
viewedfrom
front)
as
the
unit
is
removed
.

11
.
On
cars
built
3/95
and
latee
:
Use
a
spanner
toolto
ro-
tate
exhaust
sprocket
until
stop
on'
intake
sprocket
is
contacted
.
See
Fig
.
39
.
Then
slide
control
unit
off
front
of
cylinder
head
.

EMAÑ

0012514

Fig
.
39
.
On
VANOS
control
unit
withspringplate
(cars
built
3/95
and
later),
rotate
exhaust
camshaft
sprocket
clockwise
until
intake



NOTE-
camshaft
contacts
stop
.
BMW
special
tool11
5490shown
.



BMW
special
tool
no
.
113
'390
is
a
dummy
chain
ten-
sioner
and
simulates
the
function
of
thetensioner
.

VANOS
control
unit,
installing

CAUTION
-

Incorrect
installation
of
the
VANOS
control
may
result
in
damage
to
the
engine
valvetráin
.

1
.
Lock
camshafts
and
crankshaft
in
TDC
positionwith
BMW
special
tools
as
described
above
in
removal
pro-

cedure
.

CA
UTION-

The
camshafts
and
crankshaft
mustbe
locked
in
the
TDC
position
using
BMW
special
tools
no
.
11
2
300and
113
240
.
If
the
camshafts
and
crank-
shaft
are
not
at
TDC,
the
valves
can
contact
the
pistons
when
the
engine
is
turned
over
.

NOTE-

Be
sure
the
secondary
timing
chain
tensioner
is
locked
down
and
the
exhaustcamshaft
mounting
bolts
are
loosebefore
proceeding
.

2
.
Remove
primary
timing
chain
tensioner
from
side
of

cylinder
head
.
See
Fig
.
40
.

CAMSHAFT
TIMING
CHAIN



117-
1
7

Fig
.
40
.
Primary
timing
chain
tensioner
(arrow)
.
Remove
tensioner
slowlyto
relieve
spring
tension
beneath
end
plug
.

3
.
Install
BMW
special
tool
no
.
11
3
390
into
primary
tim-
ing
chain
tensionersleeve
.
Thread
tool
in
finger
tight
to
remove
chain
slack
.

4
.
Hand
turn
secondary
sprocketsclockwise
(as
viewed
from
front
of
engine)
until
sprockets
contact
stops
.

5
.
Apply
a
small
amount
of
¡¡quid
gasketsealer
(3-Bond

1209
®
or
equivalent)
to
VANOS
housing
alignment

doweis
on
front
of
cylinder
head
.
lnstall
a
new
gasket
.

6
.
Push
VANOS
piston
gear
cup
finto
VANOS
housing
until

it
bottoms
out
in
housing
.
Position
VANOS
control
unitinto
place,
but
do
not
engage
splines
on
gear
cup
.

7
.
On
cars
built
up
to
3/95
:

"
Hand
turn
exhaust
sprocketcounterclockwise
(as

viewedfrom
front
of
engine)
only
enough
to
mesh
gear
cup
splines
with
camshaft
gear
:
"
Slowly
push
VANOS
control
unit
in
untilfully
seated,
guiding
chains
in
counterclockwise
direction
.

VANOS
(VARIABLE
VALVE
TIMING)

117-
1
8



CAMSHAFT
TIMING
CHAIN

CAUTION-

It
is
crítical
that
the
exhaustcamshaft
sprocket
be

turned
only
the
mínimum
amount
necessary
to

engage
the
gear
cup
.
If
this
procedure
is
done
ín-
correctly,
the
VANOS
system
may
not
function

throughout
íts
full
range
.

NOTE-

As
the
control
unit
isinstalled,
the
secondary
sprockets
will
rotate
in
the
counterclockwise
direction
.
It
may
be

necessary
to
guide
sprockets
counterclockwise
as
the

control
unit
is
installed
.

8
.
On
cars
built
from3/95
:
Use
a
spanner
tool
(See
Fig
.

39
.),
turn
exhaust
sprocket
counterclockwise
(as

víewed
from
front
of
engine)
only
enough
to
mesh

gear
cup
splines
with
camshaftgear
.
Slowly
push

VANOS
control
unit
towards
camshaft
until
it
is
fully

seated,guiding
chains
in
counterclockwise
direction
.

CA
UTION-

Ensure
that
the
first
available
tooth
engages
.

9
.
Install
and
tightencontrol
unit
nuts
and
bolt
.

10
.
Connect
harness
connector
to
VANOS
solenoid
.
Using

new
seals,
insta¡¡
oil
line
fitting
.

Tightening
Torques

"
VANOS
control
unitto
cylinder
head

M6
nut
.....
..
..
.
.
.............
10
Nm
(89
in-lb)

M8
bolt
.....
.
.
.
.
..
.............
22
Nm
(17
ft-Ib)

"
VANOS
oil
supply
line
to
control
unit
.
32
Nm
(24
ft-Ib)

11
.
Slowlyunlock
and
release
secondary
chain
tensioner
.

12
.
Preloadprimary
chain
by
tightening
BMW
special
tool

no
.
112
240
(dummy
chain
tensioner)
to
1
.3
Nm
(11
in-
lb)
.
Then
tighten
exhaust
camshaft
sprocket
mounting

bolts
alternately
in
two
stages
.

Tightening
Torque

"
Secondarytiming
chain
sprockets
to
camshafts

(Tora
boits)

Stage
1
..
...............
...
.
.
...
5
Nm
(44
in-lb)

Stage
2
..
...............
...
.
.
..
22
Nm
(17
ft-Ib)

VANOS
(VARIABLE
VALVE
TIMING)

13
.
Remove
flywheel
locking
tool
from
transmission
bell-

housing
.
Remove
camshaft
locking
tool
from
rear
of

cylinder
head
.

14
.
Turn
engine
over
by
hand
at
least
two
fui¡
crankshaft
ro-

tations
.
Reinstall
camshaft
locking
tool
and
flywheel

locking
toolto
make
sure
all
adjustments
are
correct
.
If

settings
are
correct,
remove
locking
tools
.

15
.
Remove
BMW
special
tool
112
420
(dummy
chain
ten-
sioner)
from
side
of
cylinder
head
.
Install
primary
chain

tensioner
so
that
cutout
in
tensioner
piston
engages

chain
rail
.
See
Fig
.
34
.
Using
new
seals,
install
and

tighten
access
plugs
in
VANOS
control
unit
.

Tightening
Torque

"
Access
plugs
to

VANOS
control
unit
.
..
.
.....
.
..
...
50
Nm
(37
ft-lb)

"
Primary
timing
chain
tensioner
plug
to
tensioner
sleeve

M50/S50USengine
.
.
..
.
.
...
.
...
..
50
Nm
(37
ft-Ib)

M52/S52US
engine
...
..
...
...
...
40
Nm
(30
ft-Ib)

16
.
Install
oil
baffle
cover
above
intake
camshaft
.
Install

three
cylinder
head
covermounting
studs
to
rear
of

head
.
Instali
cylinder
head
cover
.

Tightening
Torque

"
Cylinder
head
cover

to
cylinder
head
(M6
screws)
......



10
Nm
(89
in-Ib)

17
.
Installationof
remaining
parts
is
reverse
of
removal
.

NOTE-

Be
sure
to
install
the
ground
wíres
at
the
cylinder
head
cover
mounting
studs
and
at
the
front
of
the
cylinder
head,
if
applicable
.

119-
4



LUBRICATION
SYSTEM

15
.
Remove
oil
pan
screws
.
Lower
andremove
oil
pan
to-

ward
rear
.



Tightening
Torques

"
Control
arm
bushing
carrier

CAUTION-



to
body(M10
bolt)
...............
42
Nm
(31
ft-Ib)

'



lf
the
oil
pan
does
not
separate
easily
from
the
en-



"
Engine
mount
to

gine
cylinder
block,
make
sure
all
mounting
bolis



suspension
crossmember
(M10
nut)
.
42
Nm
(31
ft-Ib)

have
been
removed
.
If
necessary,
a
few
tapswith



"
Front
suspension
crossmember
a
rubber
mallet
shouldbreak
it
free
.
Never
pry
the



to
body
.
.
..
...
..
.
....
See
310
Front
SusPension
oil
pan
loose
.
"
Oil
pan
to
engine
block
(M6
bolt)

8
.8
grade
..
....
.
...
...
.
........
10
Nm
(89
in-lb)
16
.
Installation
is
reverse
of
removal
.



10
.9
grade
...
..
.
....
..
.
.
.
.......
12
Nm
(9
ft-Ib)

"
Thoroughly
clean
all
old
gasket
material
from
mating



"
Power
steering
pump
to
bracket

surfaces
anduse
a
new
gasket
.



(self-locking
nuts)
....
..
.
....
..
.
..
22
Nm
(16
ft-Ib)

"
Applya
small
amount
of
non-hardening
sealer
(3-



"
Power
steering
pump
bracket
to
engine

Bond
O
l209
or
equivalent)
to
oil
pan
gasket
directly



block
or
oil
pan
(self-locking
nuts)
..
.
22
Nm
(16
ft-Ib)

below
joints
for
end
cover
and
front
timing
case
cover
.



"
Stabilizer
bar
link
to
control
arm
See
Fig
.
5
.



M8
nut
.................
...
.
...
22
Nm
(17
ft-Ib)
"
When
installing
oil
pan
to
engine,
tighten
forward



M10
nut
.....................
..
42
Nm
(31
Ib-ft)
screws
first,
then
tightenrear
.



"
Steering
column
universal
joint
"
Fill
engine
with
oil
as
described
in
020
Maintenance



to
steering
rack
spindle
(M8
bolt)
....
19
Nm
(14
ft-ib)
Program
.

0011950

Fig
.
5
.



Joint-mating
areas
at
oil
pan
gasket
where
sealer
should
be
applied
(arrows)
.
Apply
a
bead
3
mm
wideby
2
mm
high
.

OIL
PAN

WARNING
-

Always
use
new
bolis
when
mounting
the
subframe
to
the
body
.
The
one-timeonly
bolis
shouldbe
re-
placed
any
timethey
are
removed
.

NOTE-

The
oil
pickup
is
attached
to
the
oil
pan
using
self-tap-
ping
screws
.
For
this
reasonno
threading
for
the
pickup
is
present
on
new
oil
pans
.
Replace
the
seal
for
the
pickup
and
use
the
oíd
screws
to
rea
ttach
the
pickup
to
the
pan
.

Oil
pan,
removing
and
installing

(6-cylinder
engine,
1992models)

NOTE-

Cars
built
up
to
9/92
(1992models)usea
different
sus-
pension
crossmember
than
later
production
cars
.
Oil
pan
removalprocedureon
the
earlier
cars
requires
that
the
engine
be
raised
and
supportedfrom
above
.

1
.
Raise
car
and
place
securely
on
jackstands
.

2
.
Remove
splash
shield(s)
from
under
engine,
where
ap-

plicable
.

3
.
Drain
engine
oil
as
described
in
020
Maintenance
Pro-

gram
.

4
.
Remove
complete
exhaust
system
.
See180
Exhaust

System
.

5
.
Remove
air
filter
housing
complete
with
mass
air
flow

sensor
.
See
113
Cylinder
Head
Removal
and
Instal-

lation
.

6
.
Remove
alternator
cooling
duct
from
alternator
and
ra-
diator
support
.

7
.
Remove
radiator
cooling
fan
and
fan
shroud
.
Remove

radiator
securing
clips
at
top
of
radiator
.
See
170
Radi-

ator
and
Cooling
System
.

Center
the
steering
spindle
to
the
steering
rack
before
in-



NOTE-

stalling
the
steering
column
shaft
.
See
320
Steering
and



The
radiator
cooling
fan
nut(32
mm
wrench)
has
left

Wheel
Alignment
for
specific
installation
markings
and
pro-



hand
threads
.

cedures
.

FUEL
INJECTION



130-
3

Fuel
metering
.
The
ECM
meters
fuel
bychanging
the



The
engine
management
system
compensates
automatical-
opening
time
(pulsewidth)
of
the
fuel
injectors
.
To
ensure
that



ly
for
changes
in
the
engine
due
to
age,
minor
wear
or
small
injector
pulsewídth
is
the
only
factor
that
determines
fuel
me-



problems,
such
as
a
disconnected
vacuum
hose
.
Asa
result,
tering,fuel
pressure
is
maintained
bya
fuel
pressure
regula-



idle
speed
and
mixture
do
not
need
lo
be
adjustedas
partof
tor
.
The
injectors
are
mounted
lo
a
common
fuel
supply
called



routine
maintenance
.
the
fuel
rail
.

The
ECM
monitors
engine
speed
to
determine
the
duration



NOTE-

ofinjector
openings
.
Other
signals
to
the
ECM
help
determine



Poordriveabilitymaybe
encountered
when
the
batteryis

injector
pulse
time
for
different
operating
conditions
.
A
tem-



disconnected
and
reconnected
.
when
the
battery
is
dis-
connected,
the
adaptive
memory
is
lost
The
system
will
perature
sensor
signals
engine
temperature
for
mixture
adap-



readaptafterabout
ten
minutes
of
drfving
.
tion
.
A
throttle
position
sensor
signals
throttle
position
.
The
exhaust
oxygen
sensor(s)
signal
information
about
combus-
tion
efficiency
for
control
of
the
air-fuel
mixture
.
1992
to
1995



DISA
(Dual
Resonance
Intake
System)
engines
are
equipped
with
a
single
sensor
.
1996
and
later
(OBD
II)
engines
are
equipped
with
an
oxygen
sensor
before



TheE36
4-cylinder
engine
is
equipped
with
a
dual
intake
andone
after
each
catalytic
converter
.
Forexample,the
M52



runner
system,
termed
DISA
.
DISA
offers
the
advantages
of
engine
is
equipped
withfour
oxygen
sensors
.



both
short
and
long
intake
pipes
.
Long
intake
runners
are
most
useful
at
low
to
medium
engine
rpm
for
producing
good
Idle
speed
control
.
ldle
speed
is
electronically
controlled



torque
characteristics
.
Short
intake
runners
produce
hígherviathe
idle
speed
control
valve,
which
maintains
idle
speed
by



horsepower
at
hígher
engine
speeds
.
bypassing
varying
amounts
of
air
around
theclosed
throttle
valve
.
Idle
speed
is
not
adjustable
.



NOTE-

Knock
(detonation)
control
.
Knock
sensors
monitor
and



The
term
DISA
comes
from
the
German
words
Differen-

control
ignition
knock
through
the
ECM
.
The
knock
sensors



zierte
Sauganlage,
and
can
roughlybe
translated
as
"dif-
fering
intake
manifold
configuration
."
See
100
Engine-
function
like
microphones
and
are
able
to
convert
mechanical



General
foradditional
information
on
DISA
operation
.
vibration
(knock)
into
electrical
signals
.
The
ECM
is
pro-

grammed
to
react
to
frequencies
that
are
characteristic
of
en-



Manifold
construction
:
The
intake
manifold
is
a
two-piece
gine
knock
and
adapt
the
ignition
timing
point
accordingly
.



metal
construction,
with
a
pair
of
runners
in
thetop
section
See120
Ignition
System
for
further
details
.



and
four
runners
in
the
lower
section
.
A
butterfly
valve
is
in-
stalled
in
the
lower
section,
enabling
the
DISA
solenoid
toiso-

NOTE-



late
one
pair
of
runners
from
the
other
pair
.
See
Fig
.
2
.

The
1992
M50
engine
is
not
equipped
with
knock
sen-



Operation
.
With
the
DISA
butterfly
valve
closed,
the
pipes
sors
.
All
other
engines
are
equipped
with
two
knock



in
thetop
half
of
the
manifold
act
together
with
the
ram
air
sensors
.



pipes
in
the
lower
halfto
producea
single,
long
air
intake
pipe
for
each
cylinder
.
See
Fig
.
3
.
The
column
of
aír
oscíllating
in

Basic
Engine
Settings



this
combined
pipe
significantly
increases
engine
torque
in
the

medium
rpm
range
.

Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
arenot

adjustable
.
The
adaptive
engine
management
system
is
de-

signed
to
automatically
compensate
for
changes
in
engine
op-

eratingconditions,
although
the
adaptive
range
is
limited
.
Once

these
limits
are
exceeded,
driveability
problems
usually
be-

come
noticeable
.

Above
approximately
4,800
rpm,
the
butterfly
valve
between
the
intake
air
pipes
for
the
two
cylinder
groups
is
opened
.
The
shorter
pipes
in
the
lower
manifold
section
now
become
the

main
suppliers
of
ram
air
to
the
cylinders,yielding
greater
pow-

er
at
the
upper
end
of
the
engine
rpm
range
.
See
Fig
.
4
.

Control
components
.
The
DISA
butterfly
valve
is
actuated

NOTE-



electro-pneumatically
via
the
engine
control
module
(ECM)
.

lf
the
system
adaptive
limits
are
exceeded,
the
Check



The
valve
begins
to
open
as
engine
speed
rises
aboye
4,840

Engine
light
will
most
likely
come
on,
indicating
an



rpmand
closes
below
4,760
rpm
.
The
action
of
the
valve
is
de-
emissions-
related
fault
For
Check
Engine
light
diag-



liberately
delayed
to
prevent
it
from
opening
and
closing
repeat-
nostics,
see100
Engine-General
.



edly
within
a
short
time
.

GENERAL

The
fuel
injection
systems
used
on
the
1996
and
later
cars
covered
bythis
manual
are
OBD
II
compliant
.
This
system
is
in-
corporated
into
both
the
Bosch
M5
.2
(M44
engine)
and
the
Si-
emens
MS
41
.1
(M52/S52US
engine)
engine
management
systems
.
OBD
II
systems
use
sophisticateddiagnostic
soft-
ware
capable
of
recognizing
and
electronically
storing
hun-
dreds
of
DTCs
in
the
system
ECM
.
DTCs
can
only
be
accessed
using
special
scan
tooltest
equipment
.
The
BMW
dealer
is
equipped
with
the
specialized
OBD
II
scan
toolto
quickly
and
efficiently
locate
engine
management
problems
.
Alternately,
a
"generic"
scan
tool
can
be
used
to
access
OBD
II
fault
informa-
tion
.

NOTE-

"
At
the
time
this
manual
went
to
press,
generic
scan
tools
were
notwidely
available
for
BMW
vehicles
.
The
generic
sean
tool
is
a
specialized
toolthat
plugs
into
a
standardized
OBD
11
connector
on
1996
and
later
pas-senger
vehícles
built
for
sale
in
the
US
.

"
The
OBD
11
fault
memory
(including
an
illuminated
Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
trom
the
ECM
or
disconnecting
the
battery
will
not
erase
the
fault
memory
.

"
The
16-pin
OBD
11
diagnostic
connector
is
located
on
the
lower
left
dash
panel
.
Refer
to
Fig
.
1
.

6

1
.
Secondary
air
pump
2
.
Electric
solenoid
valve
3
.
One-way
check
valve
4
.
Intake
manifold
5
.
Exhaust
manifolds
6
.
Secondary
air
check-valve

®
G~



i

o
o



0
0
G
0000
o



,-
00

~

1111111
in

,,
0
1--

a

Fig
.
5
.



Components
of
6-cylinder
secondary
air
injection
system
.
4-
cylinder
system
is
similar
.

Secondary
AirInjection

FUEL
INJECTION



130-
5

All
OBD
II
6-cylinder
engines
are
equípped
with
asecond-
ary
air
injection
system
.
In
addition,
beginning
in
January
1997,
the
M44
engine
was
classified
as
a
TLEV
(Transitional
Low
Emission
Vehicle)
engine
and
is
also
equipped
with
sec-
ondary
air
injection
.

Typical
components
of
the
secondary
air
injection
system

are
depicted
in
Fig
.
5
.

Secondary
air
injection
usesan
electric
pump
to
pump
fresh
air
finto
the
exhaust
systemupstream
of
the
catalytic
converter
during
engine
warm-up
.
By
providing
extra
oxygen
to
the
un-
burned
fuel
in
the
exhaust,
hydrocarbons
oxidize
and
carbon

monoxide
combines
with
oxygen
to
form
carbon
dioxide
andwa-
ter
.
The
air
injection
pump
stops
within
a
specified
timed
intenral
.

4

0013120

GENERAL

130-
8



FUEL
INJECTION

Fig
.
8
.



Fuel
pump
relayterminal
identification
.
1.
Peel
back
rubber
boot
on
oxygen
sensor
electrical
har-
ness
connector
(car
wiring
side)
.
With
connector
at-
Oxygen
sensor,
testing



tached
to
sensor,
connect
digital
voltmeter
to
pins
1
(BOSch
systems
only)



and
2
in
rear
of
connector
.
See
Fig
.
10
.

CAUTION-

"
The
information
inthis
sectionapplies
to
Bosch
engine
management
systems
only
.

"
The
Siemens
MS
41
.1
system
uses
resistive-type
oxygen
sensors
.
This
sensor
uses
a
5-volt
refer-
ence
signal
input
and
the
output
to
the
ECM
var-
ees
from
1-5
volts,
in
stepped
increments
based
on
oxygen
content
in
the
exhaust
.

NOTE-

"
On
pre-08D
11(1992-1995)
cars,
there
is
one
oxygen
sensor
mounted
upstream
of
the
catalytic
convert-
er(s)
in
the
exhaust
pipe
.
See
Fig
.
9
.
"
On
OBD
11
cars
(1996-1998)
cars,
there
is
one
oxygen
sensor
before
andone
after
each
catalytic
converter
.

"
OnM52
and
S52US
engines,
the
front
pairof
oxygen
sensors
are
installed
in
the
exhaust
manifolds
.

The
oxygen
sensor
providesan
input
voltage
signal
(0-1
VDC)
to
the
ECM
based
on
the
oxygen
content
in
the
exhaust
gas
.
TO
generate
voltage,
the
sensor
temperature
must
exceed
575°F
(300°C)
.
Therefore
it
ís
electrically
heated
.

NOTE-

"
The
test
given
below
is
not
a
conclusive
test
of
oxygen
sensor
efficiency
and
does
not
test
how
quickly
the
oxygensensor
can
react
to
changing
conditions
.

"
Pin
numbers
and
wirecolors
can
vary
.
Always
check
the
wiring
diagrams
to
conflrm
wire
color
and
pinas-
signment
.

ELECTRICAL
CHECKS
AND
COMPONENT
TESTING

0013135

Fig
.
9
.



Oxygen
sensor
location
(arrow)
ahead
of
catalytic
converter
.
3181
model
with
M42
engine
shown
.

1
.
Black
(ground)
2
.
Grey
(signal)



4
.
White
(heater
circuit)
3
.
White
(heater
circuit)

0013189
Fig
.
10
.
Oxygen
sensor
connector
terminal
identification
(sensor
sede)
.
Terminals
numbers
are
molded
into
connector
.

2
.
Start
engine
.
Oxygen
sensorshould
start
to
output
a
fluctuating
voltage
within
a
short
period
.
If
voltage
is
in-
correct,
turn
engine
off
and
check
preheater
circuit
as
described
below
.

WARNING
-

Exhaust
manifolds
and
pipes
can
be
hot
enough
to
cause
serious
burns
.
Wear
suitable
heavy
gloves
and
other
appropriate
protection
.

Oxygen
Sensor
FUEL
DELIVERY
TESTS
FUEL
INJECTION



130-
9

"
Voltage
at
¡dle
..
.
..
..
....
0
.2
to
0
.8
VDC,
fluctuating



Checking
fuel
delivery
is
afundamental
part
of
trouble-
shooting
and
diagnosing
the
engine
management
system
.
Fuel
pressure
directly
influences
fuel
delivery
.
An
accurate

NOTE-



fuel
pressure
gauge
will
be
needed
to
make
the
tests
.

To
check
sensorresponse
to
lean
and
rich
mixtures,
createenairleak,
orpull
vacuumhoseofffue¡
pressure



There
are
three
significant
fuel
delivery
values
to
be
mea-

regulator
to
increase
fuel
pressure
.



sured
:

3
.
Separate
sensorharness
connector
from
sensor
.
Check

for
battery
voltage
between
terminals
3
and
4
(green

wire
and
brown
wire)
in
main
wiring
harness
side
of
con-

nector
with
engine
running
.
If
voltage
is
not
present,

check
oxygen
sensor
heater
relay
.
See610
Electrical

Component
Locations
.

4
.
Check
heater
element
resistance
between
terminals
3
and
4
in
sensor
side
of
connector
.
If
element
is
electri-

cally
open
(no
continuity),
replace
sensor
.

NOTE-

The
oxygen
sensor
heater
relay
is
mounted
in
the
main
power
distributfon
box
in
the
left
rear
of
the
engine
com-
partment
.
Refer
to
Fig
.
6
.
The
heater
relay
is
energized
wíth
positive
(+)
battery
voltage
from
the
main
relayanda
switched
ground
from
the
ECM
.
See
Electrical
Wir-
ing
Diagrams
.

"
Oxygen
sensor
to
exhaust
pipe
...
..
55
Nm
(41
ft-Ib)

"
System
pressure-created
by
the
fuel
pump
and
main-
tained
by
the
pressure
regulator
.

"
Fuel
delivery
volume-created
by
the
fuel
pump
and
af-
fected
by
restrictions,
suchasclogged
fuel
filter
.

"
Residual
pressure-the
pressure
maintained
in
the
closed
system
after
the
engine
and
fuel
pump
are
shut

off
.

Procedures
for
measuring
the
first
two
quantities
arede-
scribed
in
160
Fuel
Tank
and
Fuel
Pump
.
Residual
fuel
pres-
sure
is
checked
using
the
procedure
detailed
later
in
this

group
.

Operating
fuel
pump
fortests

To
operate
the
fuel
pump
for
testing
purposes
without
hav-

íng
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to

power
the
pump
directly
.
Fuel
pump
relay
location
is
shown
in

Fig
.
6
.

5
.
¡f
oxygen
sensor
doesn't
produce
a
fluctuating
voltage



To
runthe
fuel
pump,
remove
the
fuel
pump
relay
and
con-
and
preheater
circuit
is
OK,
replace
sensor
.



nect
the
socket
for
relayterminal
30
to
the
socket
for
relay
ter-

mina¡
87
with
a
fused
jumper
wire
.
After
completing
the
tests,

NOTE-



remove
the
jumper
wire
.

If
not
already
applied,
coat
the
oxygen
sensor
threads
with
an
anti-seize
compound
before
installation
.
Do
not



CAUTION-
getthe
compound
on
the
sensor
tip
.
"
Relay
locations
may
vary
.
Use
care
when
identi-
fying
relays
and
making
electrical
checks
at
the
fuselrelay
panel
.
See
610
Electrical
Compo

Tightening
Torque



nent
Locations
for
additional
relay
information
.

"
The
fuel
pump
relay
has
a
1
.5
mm2
red
wire
at
ter-
minal
30
in
the
relay
socket
.
Terminal
87
has
a
1
.5
mm
2
greenlviolet
wire
.
See
Electrical
Wiring
Di-
agrams
for
additional
wiring
information
.

NOTE-

Thejumper
wire
should
be
1.5
mm2
(14
ga
.)
and
in-
clude
an
in-line
tuse
holder
with
a15
amp
tuse
.
To
avoid
fuselrelay
panel
damage
from
repeated
connect-
ing
and
disconnecting,
also
include
a
toggle
switch
.
A
heavy-duty
jumper,
BMW
tool
no
.
61
3
050,
is
also
available
from
an
authorized
BMW
dealer
.

FUEL
DELIVERYTESTS

160-2



FUEL
TANK
AND
FUEL
PUMP

0011943
1
.
Filler
pipe



10
.
Fuel
compensating
siphon
pump
and
hose
assembly
2
.
Filler
pipe
grounding
tab



(models
built
from
1/95)
3
.
Vent
pipe



11
.
Fueltank
4
.
Threaded
collar



12
.
Tank
support
strap
5
.
Rubber
ring
seal



13
.
Bolt-tighten
to
23
Nm
(17
ft-Ib)
6
.
Fuel
pump



14
.
Fuel
expansion
tank
7
.
Left
side
fuel
leve¡
sender(models
built
from
1/95)



15
.
Fuel
tank
pressure
sensor
(OBD
II)
8
.
Right
side
fuel
leve¡
sender9
.
Left
side
fuel
leve¡
sender
with
fuel
compensating
siphon
pump
(models
built
up
to
1/95)

Fig
.
1
.



E36
fuel
tank
assembly
.

FUEL
TANK
AND
LINES



Fuel
tank,
draining

The
plastic
fuel
tank
is
mounted
beneath
the
center
of
the
car
(beneath
rear
seat)
.
Mounted
in
the
fuel
tank
are
the
fuel
pump
and
fuel
leve¡
sending
units
.
Connecting
lines
for
the
evaporative
emission
control
systemand
expansion
tank
are
also
attached
to
the
tank
.
When
performing
the
procedures
that
follow,
refer
toFig
.
1
.

Fuel
tank
capacity
for
E36
modeis

"All
ex
.
1996
M3
(3
.0
L)
.....
.
..
..
65
liters
(17
.0
gal)

"
1996
M3
(3.0L)
modeis
.
...
.
..
.
.62
liters
(16
.4
gal)

FUEL
TA
NKAND
LINES

The
fuel
tank
should
be
drained
into
an
approved
storage
unit
or
another
car's
fuel
tank
.

WARNING
-
"
Before
removing
the
tank,
be
sure
that
afl
hot
components
such
as
the
exhaust
system,
are
completely
cooled
down
.

"
Fuel
may
be
spilled
.
Do
not
smoke
or
worknear
heaters
or
other
Pire
hazards
.

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
paga
vi¡¡
.